Reducing room noise and soundproofing walls can be accomplished using a variety of systems.
Acoustic foam is the best type of insulation for soundproofing your wall because it is designed specifically to absorb sound. It looks a lot like an oversized egg carton. The unusual shape of the foam traps the sound being produced in the room. Determine the amount of foam you will need. Apply a foam adhesive to a small area of one of the walls. Place the foam on the area with the adhesive. Firmly press the foam into the adhesive until it is stuck to the wall. Continue the process until the wall is completely covered. Continue with the other walls in the room. A staple gun can also be used to secure the foam to the wall.
Cutting large pieces of recycled carpet to fit the walls will also work in reducing room noise. The carpeting can be cut into panels and adhered to the wall using screws or a staple gun.
Attach furring strips to the walls in the room requiring soundproofing. Cover the the strips with vinyl panels. Apply a silicon adhesive to the the panel seams. Attach another drywall layer over the vinyl. This system will work well in reducing room noise.
Cardboard egg cartons are another easy and inexpensive solution to noise reduction. You will need to collect as many cartons as possible. Have your family and friends help out in the collection. Attach the cartons to the wall with the side that is bumpy facing into the room. Use a staple gun to secure the cartons in rows. Although egg cartons won't be as effective as acoustic foam, they will certainly be much cheaper.